Canon G7X Tech Info
Canon G7X Technical Info
by Mike Tomkins | Posted: 09/15/2014
Canon hasn't revealed the manufacturer of the image sensor used in the PowerShot G7X digital camera, but we note with interest that its specifications look a whole lot like the Sony-manufactured silicon used in the competing RX100 II and III. (And from the announcement of the DxO One, we know that sensor is available to third-parties for their own designs.)
Like that chip, the Canon G7 X's imager is a 1.0"-type, backside-illuminated CMOS image sensor. Where Sony refers to its chip as an Exmor R type, though, Canon refers to that in the G7X simply as being "High-Sensitivity CMOS".
And resolution, too, is essentially identical. The G7X sensor has a 3:2 aspect ratio and an effective resolution of 20.2 megapixels from a total of 20.9 megapixels. Maximum image dimensions are 5,472 x 3,648 pixels, all identical to the Sony.
Could it be that Canon is using its main rival's sensor in the G7X? It seems possible, but unless somebody does a teardown of the Canon camera, there's simply no way to be sure.
Output from the Canon G7X's image sensor is handled by a DIGIC 6 image processor. That's the same generation used in the larger-sensored Canon G1 X Mark II, as well as in the smaller-sensored Canon S120, the two models between which the G7X sits in Canon's enthusiast compact camera lineup.
Together, the G7X's sensor and processor pair to allow a working sensitivity range of ISO 125 to 12,800 equivalents. That's identical to the range provided by the Sony RX100 III and IV by default, but on the Sony camera it can be extended to ISO 80 at the bottom end, or ISO 25,600 at the top end. Canon does not provide any ISO expansion capability on the G7X.
You can, of course, achieve the same thing as Sony's lowest ISO sensitivity with the G7X by simply overexposing and then dialing back the exposure post-capture, but you'll reduce dynamic range and potentially lose highlight detail in the process, just as you will with in-camera expansion. (That's why the RX100 III and IV's expanded range isn't available by default.)
In terms of burst-shooting performance, the sensor/processor pairing of the Canon G7X looks to win against Sony's BIONZ X in one respect, but trails in others. With autofocus enabled, Canon says you'll extract 4.4 JPEG frames per second with its camera, where Sony pledges just 2.9 fps in the same condition.
Lock focus and exposure from the first frame, though, and the Canon G7 X is said to yield 6.6 fps when shooting JPEGs, where the Sony RX100-series cameras can all manage at least 10 fps.
However our lab testing has revealed an Achilles heel: The G7X's burst rate slows considerably when shooting RAW files, to only about 0.7 fps with continuous autofocus enabled, or between 1.0 and 1.2 fps with autofocus and exposure locked. See our Canon G7X Performance page for details.
It's worth noting that in this respect, the little G7X bests its bulkier siblings, the G1 X and G1 X Mark II, at least when shooting JPEGs. Both figures are blown away by another enthusiast compact, however, albeit one that sits somewhere between the G7X and G1X-series cameras in size. The simultaneously-announced Panasonic LX100 can draw 6.5 frames per second from its much larger 4/3-inch sensor with autofocus, and 11 fps without.
Fixed zoom lens
Although we've found much to love in Sony's RX100-series cameras, one thing we've long bemoaned is their relatively short zoom reach, something that has only become more restrictive as the company traded focal range for a brighter aperture in the most recent RX100 III model. If you've been right there along with us, begging for more reach, you're going to be thrilled by the Canon G7X -- on paper at least.
It might not bear the Zeiss Vario-Sonnar T* branding of Sony's cameras, nor the Leica DC Vario-Summilux badge of the Panasonic LX100, but this Canon-branded optic nevertheless looks impressive. (To see how it performed in our tests, see our G7X Optics page.)
The reason? In a body barely any larger -- and actually just microscopically slimmer -- than the Sony RX100 III and IV, the Canon G7X packs in almost 50% more zoom range, and it doesn't even compromise on maximum aperture to do so!
Where the Sony RX100 III and IV sport a 2.9x, 24 to 70mm-equivalent zoom, the earlier RX100 and RX100 II shared a 3.6x, 28-100mm equivalent optic, and the Panasonic LX100 has a 3.1x, 24 to 75mm lens, Canon blows them away with a 4.2x, 24-100mm optic. That gives you greater telephoto reach than the RX100 III or IV, or the Panasonic LX100, all while matching their wide-angle. And simultaneously, it beats the RX100 and RX100 II for wide-angle shooting while matching their telephoto.
And best of all, it does so while providing an f/1.8 aperture at wide angle or f/2.8 at telephoto, matching the aperture range of the RX100 III and IV despite all that extra tele reach. Compared to the RX100 and RX100 II, the difference is stark: Canon gives you a bright f/2.8 at telephoto, while Sony can manage only f/4.9. Panasonic, meanwhile, has a slight edge at wide angle with an f/1.7 maximum aperture, but only matches the Canon G7 X at telephoto, despite a significantly larger, thicker body.
Another plus for the Canon G7X's lens is that it has a nine-bladed, rounded aperture diaphragm that should help it to yield more attractive bokeh, compared to the 7-bladed, rounded apertures of Sony's RX100 siblings. Panasonic's LX100 has the advantage here, though, thanks to its sensor size and the fact that it, too, has a 9-bladed, rounded aperture. The 1"-type sensors of the Canon and Sony models simply won't provide the same opportunities for depth-of-field blur that you'll get with the larger 4/3"-type sensor in the Panasonic, even if the LX100 doesn't use the entire sensor area in any given aspect ratio.
Oh, and one last great piece of news for potential Canon G7 X customers: a built-in 3-stop neutral density filter is provided. Among its main rivals, only the Sony RX100 III and IV have a built-in ND filter, also good for a 3-stop reduction in incoming light.
As you'd expect in this class of camera, the Canon G7X includes true optical image stabilization. Canon rates its effectiveness at 3 stops of correction at full telephoto, and notes that it has eight different working modes which can be accessed automatically in Intelligent IS mode.
Canon brands the autofocus system of the G7 X as "High Speed AF", and as we've already mentioned, continuous AF performance looks handy compared to the RX100-series cameras.
Canon's AF system also bests Sony in another metric, though, providing a selection of 31 autofocus points that cover most of the image frame, where the RX100 trio all share the same 25-point AF system. According to Canon, the G7 X's AF points encompass 80% of the frame height and 84% of the width, leaving bands of just 10% at the top and bottom uncovered, along with 8% bands at frame left and right.
Face detection is also included, as is an autofocus assist lamp. Although we don't know the working range of the G7X's AF system, nor the camera's maximum magnification, we do know that it can focus down to just 2.0 inches at wide-angle, almost as close as the 1.9 inches of Sony's cameras at wide-angle.
Like the original Sony RX100 and RX100 II (unless you count the latter's expensive, optional accessory, anyway), the Canon G7 X forgoes an electronic viewfinder. It's a decision that doubtless helps save some size, but means that you'll be limited to shooting at arm's length -- unlike those shooting with the RX100 III or IV, or Panasonic LX100.
Thankfully, the Canon G7X's rear-panel, 3.0-inch LCD monitor matches the 3:2 aspect ratio of its image sensor, so unlike its RX100-series rivals which all use 4:3 screens, you'll see a larger preview / review image with no black borders if you're shooting in the native sensor aspect ratio.
(Things are more complicated with the LX100, because none of its aspect-ratio options precisely match the sensor aspect, so if you prefer shooting 4:3-aspect images then that model's screen makes sense.)
The G7X's display also bests its rivals in pixel count thanks to its wider 720 x 480 pixel array, where the LX100 and RX100-series all sport 640 x 480 pixel screens. Coverage is 100%, so you'll be able to take advantage of those extra pixels for accurate framing, too, not just when chimping your shots post-capture.
In terms of dot count, though, the G7X has only red, green, and blue subpixels at each pixel location, where the RX100-series cameras all use WhiteMagic displays that include an additional white subpixel. Without that fourth dot per pixel, the G7X has a lower dot count, and its screen will either be dimmer than a WhiteMagic screen at equal power consumption, or use more power for equal brightness.
But there's one respect in which the Canon G7X bests all its rivals. The Canon G7 X is far and away the most compact large-sensor, fixed-lens zoom camera with a touch screen display. In fact, the only other camera in the category with a touch screen is the much larger G1 X Mark II.
Specifically, the Canon G7X monitor is a capacitive touch screen, just like you'd find on a smartphone.
The Canon PowerShot G7X offers most if not all of the main exposure features you'd expect of an enthusiast camera, plus a selection of consumer-friendly options which acknowledge that it's not just experienced photographers who want the versatility of a pocket camera coupled with the image quality of a far larger sensor than a typical compact or camera phone.
Exposure modes on offer include Auto, Hybrid Auto, Program (with Program Shift), Aperture-priority, Shutter-priority, Manual, Custom, Scene, Creative Shot, Creative Filters, and Movie. There are a relatively restrained total of seven scene modes -- Portrait, Smart Shutter, Star, Handheld Night Scene, Underwater, Snow, and Fireworks.
Exposures are determined using evaluative, center-weighted or spot metering, but like Sony before it, Canon hasn't disclosed the number of areas into which its evaluative system breaks down the scene, nor its metering system working range. We can confirm, however, that both autoexposure lock and exposure compensation are provided, with the latter having a working range of +/-3EV in 1/3 increments set using a dedicated dial on the top deck. A 3-shot exposure bracketing mode is also availble with a range up to +/2EV in 1/3 increments.
Shutter speeds range from 1/2,000 to 250 seconds, a very wide range that does have some limits: Beyond 1.3 seconds, you can't roam past ISO 3,200 equivalent, and once you reach 40 seconds you're limited to ISO 125 max. The fastest shutter speed of 1/2,000s is identical to those of the RX100-series cameras, but bested by the Panasonic LX100's 1/4,000s top speed. And unlike the LX100, the G7X offers no electronic shutter function.
A generous selection of white balance modes are provided. These include Auto, Multi Auto, eight white balance presets, two custom positions, and the ability to fine-tune white balance.
Like all of its closest rivals except for the Panasonic LX100, the Canon G7X includes a built-in popup flash strobe. It's deployed using a mechanical release on the left side of the camera body, and when raised, sits just a little above and forwards of the camera body. There's no hot shoe, unlike in the competing Panasonic LX100 and Sony RX100 II.
Flash modes include Auto, On, Slow Sync Synchro and Off, with red-eye reduction as well as 1st and 2nd curtain options. A Manual flash mode with 3 output levels is also available.
Maximum flash sync speed is 1/2000 second and the built-in strobe is said to have a working range of 20 inches to 23 feet (50cm to 7m) at wide angle, or 16 inches to 13 feet (40cm to 4m) at telephoto. The ISO speed isn't stated, so can probably be assumed to be using Auto ISO, just as Panasonic and Sony do in their own specs. The range at base ISO will thus be quite a bit shorter.
The flash has a rather lengthy manufacturer-rated recycle time of ten seconds (we measured 6.2 seconds with a fully-charged battery in the lab), +/- 2.0EV of flash exposure compensation is provided, and FE Lock is supported.
Photo effects options include My Colors Off, Vivid, Neutral, Sepia, Black & White, Positive Film, Lighter Skin Tone, Darker Skin Tone, Vivid Blue, Vivid Green, Vivid Red, and Custom Color. Possible adjustments (as relevant to the effects mode) include contrast, sharpness, saturation, red, green, blue and skin tone, so you can tweak results to your taste.
Creative Filters are accessed through their own Mode dial position, and include High Dynamic Range, Nostalgic, Fisheye Effect, Miniature Effect, Toy Camera Effect, Background Defocus, Soft Focus, Monochrome, Super Vivid and Poster Effect.
A self-timer function is provided with preset durations of two or ten seconds plus a custom option, and a dual-axis level gauge helps to get horizons level and verticals parallel.
There's no built-in panorama function, but otherwise the selection of creative tools seems pretty complete.
Like most cameras these days, the Canon G7X can shoot high-definition or standard-definition videos, not just stills. Movies are recorded with MPEG-4 AVC / H.264 compression and include MPEG-4 AAC-LC stereo audio from an internal microphone; there is no external mic jack. A wind filter is available with Auto and Off settings.
Resolution options include Full HD (1,920 x 1,080 pixels; 1080p), HD (1,280 x 720 pixels; 720p) and VGA (640 x 480 pixels; 480p). At Full HD resolution you have a choice of 30p or 60p progressive-scan frame rates, while at lower resolutions you're restricted to 30p only. Sorry, no 24p support. Maximum clip length is 29 minutes and 59 seconds, or up to 4GB file size.
Exposure modes available for videos include: Smart Auto (21 scenes detected), Standard, Program, Portrait, Nostalgic, Monochrome, Super Vivid, Poster Effect, Underwater, Snow, and Fireworks. A Manual movie mode allows you to select aperture, shutter speed (1/30s and above) and ISO (up to 3,200), and even allows adjustments on-the-fly.
+/-3EV exposure compensation is available, but must be set before recording begins, and exposure lock is supported. Optical zoom is available during recording, as is continuous AF and touch focus. Some high-end video features such as levels control, zebra striping, uncompressed HDMI output, or high-res stills during video capture are however not supported unlike some of the G7X's rivals.
One option Canon offers that its rivals don't, is a special Star Time-Lapse Movie mode. This allows only Full HD resolution at a playback rate of 30 or 15 frames per second, and captures only one frame every 30 seconds. (You have no control over the interval.) In other words, you're playing back at either 450x or 900x real-time. You can choose whether or not the stars should have "tails" -- that is, that as they move across the frame their earlier positions should remain bright or return to darkness. If the tail is enabled, you can choose how long it should remain for in three levels.
Other special movie options include iFrame (intended for use with Apple software like iMovie or Final Cut), Miniature Effect (HD or VGA at 1.5, 3, or 6 fps), and Digest Movie (HD at 30fps; records a brief movie clip before each still, then assembles a single digest movie per day from all the clips.)
Ensuring that it stays relevant in the smartphone age, the Canon G7X includes built-in Wi-Fi wireless networking technology (IEEE 802.11b/g/n), as well as support for Near-Field Communications technology.
NFC is something that came to Android about four years ago now, and has since become widespread on Blackberry, Symbian and Windows Phone devices too. It's also included in the latest-generation iPhone 6 models, but sadly locked down so that it can only be used for Apple Pay payment.
With NFC on an Android 4.0+ device, all you do is simply bump the devices to be paired together briefly, ensuring the locations of their antennas are near each other. (NFC has a very, very short range that acts as a security feature.) Once the devices see each other via NFC, they can then automatically negotiate a much faster, longer-range Wi-Fi connection, and the NFC tech can also be used to have the smartphone run the relevant app for you automatically, saving you launching it yourself.
The requirement for a specific app invariably rules out platforms other than the big two -- Android and iOS -- though, and that's the case here too, leaving Blackberry, Symbian and Windows Phone users looking on with jealousy. Those photographers using iOS 6.0+ or Android 2.3.3+, though, can look forward to quick and easy sharing through their phone or connected tablet on social networks and the like, as well as support for wireless remote shooting and geotagging images.
Connectivity options in the Canon PowerShot G7X include standard-definition video output in NTSC or PAL formats (a feature Sony's RX100-series cameras lack), as well as high-definition video output and USB for data transfer.
The HD output is a Micro HDMI port, and the SD video / USB outputs share a single connector. As mentioned previously, the G7X's HDMI port is not capable of providing a clean, uncompressed video feed for external recording and is meant only for playback.
The Canon G7 X stores images on Secure Digital cards, as do almost all higher-end cameras these days. Both the higher-capacity SDHC and SDXC types are supported, and so are the higher-speed UHS-I types. (Sony only recently added support for the latter in its RX100 III model; earlier Sony models will simply fall back to standard speeds with UHS-I cards, likely making read / write times longer than in the Canon G7 X.)
Still images can be stored in 12-bit raw or compressed JPEG formats, or both simultaneously.
The G7X draws power from a proprietary NB-13L lithium-ion battery pack. With a rated 3.6 volts, 1,250 mAh, and 4.5 Wh capacity, the pack is near-indistinguishable from that in the RX100-series cameras, but Canon specifies significantly lower battery life.
Where the RX100-series cameras will manage 280-350 shots on the LCD monitor right out of the box, Canon's camera is rated as good for 210 shots ordinarily, or 310 shots in ECO mode which dims and then turns off the LCD more quickly when the camera is not in use.
An optional ACK-DC110 AC adapter kit which includes a dummy battery is available.
The good news is that while battery life is perhaps shorter, charging batteries is less troublesome. Unless you pay extra for an external charger, Sony's RX100 cameras charge in-camera via USB, meaning you can't charge a second battery while you're out shooting. Canon, though, gives you that option by simply including a standalone charger.
The downside is that you'll need to bring an extra piece of gear with you on trips, rather than simply sharing the same USB charger between devices.
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